Fetal MRI prior to intrauterine surgery of open neural tube defects: What does the radiologist need to know.

The management of myelomeningocele study trial showed significant prognostic improvement in fetal repair before 26 weeks of gestation. Hence, surgery in utero represents the best treatment option for open-neural tube defects (NTDs). Fetal surgery of open-NTDs has specific inclusion and exclusion criteria, which can be adequately studied with fetal MRI. The main concern: the spine (spinal defects other than Myelomeningocele and Myeloschisis, the level of the lesion higher than T1 or lower than S1 and the degree of kyphosis ≥ 30°), the skull/brain (no cerebellum herniation and Chiari II malformation and the presence of any intracranial abnormality unrelated to open NTDs), the uterus (cervix length less than 2 cm, multiple gestations and placental and uterine abnormalities) and any other fetal abnormality not attributed to spinal defect. In this review, we describe the fundamental role of fetal MRI in supporting therapeutic decisions in pre-surgery intrauterine planning through the accurate and comprehensive description of findings, providing a proposal of a structured report. In addition, we describe how post-surgical MRI is important in investigating the effectiveness of surgery and detecting repairing complications.

Features of cystadenofibroma on magnetic resonance imaging: an update using the O-RADS lexicon and considering diffusion-weighted and perfusion imaging.

PURPOSE: Cystadenofibroma (CAF) is a rare tumour of the ovary that can be confused with a borderline or malignant lesion due to its morphological characteristics. The study aims to analyse the MRI (magnetic resonance imaging) features of histologically proven ovarian cystadenofibromas according to lexicon-based and O-RADS (Ovarian-Adnexal Reporting and Data System) descriptors, with particular attention to time-intensity curves (TIC) and Diffusion-Weighted sequences (DWI); we also wanted to test the performance of O-RADS MRI risk stratification system in this particular subgroup of patients. METHODS: We have included all patients who performed MR between October 2019 and December 2021 after an inconclusive trans-vaginal ultrasound. All patients underwent surgery with histological results of CAF. According to the O-RADS lexicon, we reported the morphological characteristics of each lesion and their appearance in the perfusion-weighted imaging (PWI) and DWI sequences. We assessed the risk of malignancy for each lesion through O-RADS MRI score. RESULTS: Twenty-one histologically proven CAF were analysed, of which 20 benign and one borderline with degeneration into adenocarcinoma. We described the typical morphological characteristics of CAF according to lexicon-based and O-RADS descriptors. Analysis of time-intensity curves (TIC) in PWI sequences showed a slow and progressive enhancement of solid tissue (type I curve), configuring an O-RADS score of 2 or 3, except for the only malignant lesion that showed a type II curve and restriction in DWI (O-RADS 4). CONCLUSIONS: Our study is the largest comprising PWI and DWI sequences, highlighting their pivotal role. O-RADS score correctly classified the masses as benign or malignant.